An aircraft is provided with position lights that indicate a travelling direction and a position so as to prevent a mutual collision. It is provided that an aircraft is equipped with a green position light at the end section of the right wing, a red position light at the end section of the left wing, and a white position light at the tail section thereof. While incandescent lamps have been used as light sources of the conventional position lights, light emitting diodes (LEDs) have been used recently. See, for example, Japanese Patent Laid-Open Publication No. 2007-513488.
For aircraft position lights, irradiation angles are prescribed. For example, an irradiation angle of 110° toward outside in relation to an axial line in the travelling direction is prescribed for both wing tip position lights and an irradiation angle of 140° is prescribed for a tail section position light. Therefore, in the position lights using LEDs, light beams emitted from the LEDs are required to be properly controlled to satisfy the prescribed irradiation angles.
The present disclosure has been made in consideration of the problems as described above and an object thereof is to provide a lamp which is capable of controlling an irradiation angle properly.
In order to achieve the object, a lamp according to an aspect of the present disclosure includes: a light emitting unit including a semiconductor light emitting element and a reflector which has a reflecting surface configured to reflect light from the semiconductor light emitting element. The reflecting surface of the reflector is formed to have a parabolic shape in a cross-section perpendicular to an optical axis of the semiconductor light emitting element. In addition, the reflecting surface is formed to have a condensing-diffusing shape in a cross-section parallel to the optical axis of the semiconductor light emitting element to condense and diffuse reflected light beams in a forward direction.
The lamp may be provided with two light emitting units which are disposed in a substantially horizontal direction thereof. The two light emitting units may be arranged such that the reflecting surfaces of the reflectors face each other.
The lamp may be provided with two light emitting units which are disposed in a substantially horizontal direction thereof. The two light emitting units may be arranged such that the reflecting surfaces of the reflectors of the light emitting units are positioned back to back.
The lamp may be provided with a plurality of light emitting units which are disposed in a substantially vertical direction thereof.
The condensing-diffusing shape may be an ellipse shape.
According to the present disclosure, a lamp capable of controlling an irradiation angle properly may be provided.
The above-described summary is illustration purposes only and does not intend to limit in any ways. In addition to the illustrative embodiments, examples, and features described above, additional embodiments, examples, and features will become apparent by referring to the drawings and the following detailed descriptions.